UPnP requests accepted over router WAN interfaces

Vulnerability Note VU#357851

Overview

Description

Universal Plug and Play (UPnP) is a networking protocol mostly used for personal computing devices to discover and communicate with each other and the Internet. Some UPnP enabled router devices incorrectly accept UPnP requests over the WAN interface. "AddPortMapping" and "DeletePortMapping" actions are accepted on these devices. These requests can be used to connect to internal hosts behind a NAT firewall and also proxy connections through the device and back out to the Internet. Additional details can be found in Daniel Garcia's whitepaper, "Universal plug and play (UPnP) mapping attacks". [PDF] A list of devices reported to be vulnerable can be found on the UPnP hacks website.

Impact

A remote unauthenticated attacker may be able to scan internal hosts or proxy Internet traffic through the device.

Solution

Contact the device's vendor to find out if a firmware update is available to address this vulnerability.